Balloon catheter with balloon retaining sleeves

ABSTRACT

A catheter having a flexible annular balloon secured on a shaft of the catheter by a pair of annular sleeves. A method is provided for securing the balloon to the shaft by shrinking the sleeves over grooves of the shaft. The balloon is inverted over the grooves prior to shrinking the sleeves into the grooves.

SUMMARY OF THE INVENTION

The present invention relates to catheters and methods for fabricatingsuch catheters.

A various assortment of catheters has been proposed for use on patients,such as endotracheal tubes and Foley catheters, in which the cathetershave an inflatable balloon secured onto the catheter shafts. During useof the endotracheal tubes, the inflated balloons seal and retain thecatheter in the patient's trachea, while the balloons of Foley orurinary catheters are inflated in the patient's bladder in order toretain the catheters in place.

The catheter balloons are made from a flexible material which isnormally elastic, while the catheter shafts are preferably made from amore rigid material to permit easy placement and provide greaterstructural integrity of the shafts during use. Accordingly, in manycases it has become desirable to make the balloons and shafts fromdifferent materials, such as a silicone balloon for a non-siliconeshaft, in order to achieve the desired characteristics required by thecatheter balloons and shafts. In practice this has proven difficult toaccomplish, since many of the dissimilar materials are not susceptibleto conventional bonding techniques. Thus, the different materialsfrequently prove incompatible when attempts are made to attach theballoon to the shaft through use of heat sealing or known adhesives, andfrequently a satisfactory bond cannot be obtained between the balloonand shaft in a conventional manner.

SUMMARY OF THE INVENTION

A principal feature of the present invention is the provision of animproved catheter and a method of fabricating the catheter in asimplified manner.

According to a method of the present invention a flexible annularballoon is secured on a shaft of the catheter by forming a pair ofspaced annular grooves in an outer surface of the shaft, positioning afirst end portion of the balloon intermediate a first shrinkable annularsleeve and one of the grooves, and shrinking the first sleeve to securethe first end portion of the balloon in the one groove. The remote endportion of the balloon is positioned intermediate a second shrinkableannular sleeve and the other of the grooves, and the second sleeve isshrunk to secure the remote end portion of the balloon in the othergroove.

Thus, a feature of the present invention is that the balloon is attachedto the shaft by shrinking the sleeves while securing end portions of theballoon in the grooves of the shaft.

Another feature of the present invention is that the balloon is securedon the shaft in a simplified manner.

Yet another feature of the invention is that the balloon may be securedto the shaft while obtaining an excellent bond between the balloon andshaft without the necessity of adhesives or sealing.

Still another feature of the invention is that the balloon may bereadily secured to the shaft in spite that the balloon and shaft may bemade from dissimilar materials which otherwise could not be bonded in asuitable manner.

A further feature of the invention is the provision of a catheter havinga balloon secured to the catheter shaft in accordance with a method ofthe present invention.

Further features will become more fully apparent in the followingdescription of the embodiments of this invention and from the appendedclaims.

DESCRIPTION OF THE DRAWINGS

In the drawings:

FIG. 1 is a fragmentary elevational view of a catheter of the presentinvention;

FIG. 2 is a fragmentary sectional view of an elongated shaft of thecatheter of FIG. 1;

FIG. 3 is a perspective view of an annular sleeve utilized to secure anend portion of a balloon to the catheter shaft;

FIGS. 4-6 are fragmentary elevational views, taken partly in section,illustrating steps during securement of the balloon to the cathetershaft; and

FIG. 7 is a fragmentary sectional view of the catheter illustrating theballoon as secured to the shaft according to a method of the presentinvention.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

Referring now to FIG. 1, there is shown a catheter generally designated10 having an elongated shaft 12, an opening 14 adjacent a distal end 16of the shaft 12, and a balloon 18 of flexible material, such assilicone, secured to the shaft 12 in accordance with a method of thepresent invention. Although for convenience the catheter 10 isillustrated in the form of an endotracheal tube, it will be apparentthat the principles of the present invention are equally applicable toother catheters, such as Foley or urinary catheters.

With reference to FIG. 2, the catheter shaft 12 has a main lumen 20extending through the shaft and communicating with the opening 14 at thedistal end 16 of the shaft 12. Also, the shaft 12 has an inflation lumen22 in a wall 24 of the shaft 12 which communicates with an outer surface26 of the shaft 12 through an aperture 28 in the wall 24. As shown, anouter end 30 of the inflation lumen 22 is blocked by a suitable plug 32,and the catheter 10 may have a tube or side arm 34 connected to theshaft 12 and defining an extension of the inflation lumen 22, such thatfluid may be passed through the tube 34 and inflation lumen 22 tocontrol inflation and deflation of the balloon 18 when secured to theshaft. The shaft 12 also has a pair of spaced first and second annulargrooves 36 and 38 defining recesses in the outer surface 26 of thecatheter shaft 12.

With reference to FIG. 3, the securing means comprises an annular sleeve40 of shrinkable material having a bore 42 extending through a wall 44of the sleeve 40. As will be seen below, first and second sleeves ofsimilar structure are utilized to secure the balloon onto the cathetershaft, and for convenience the first and second sleeves will bedesignated by the reference numerals 40a and 40b during the followingdescription. The sleeves 40a and b may be made of any suitablethermosetting or thermoplastic heat shrinkable material, such aspolyethylene or polyvinyl chloride, in order that the sleeves shrink toa reduced size responsive to heating.

With reference to FIG. 4, the balloon 18 comprises an elongated annularsleeve of flexible material having a first end portion 46 defining afirst end edge 48 of the balloon 18, and a second opposed end portion 50defining a second end edge 52 of the balloon 18. As shown, prior toshrinking, the first sleeve 40a has an internal diameter greater thanthe outer diameter of the catheter shaft 12, and, in accordance with amethod of the present invention, the first sleeve 40a is positioned overthe location of the first groove 36 of the shaft. The first end portion46 of the balloon 18 is positioned intermediate the first sleeve 40a andthe first groove 36 with the first end edge 48 of the balloon 18 beingdirected toward the second groove 38, as shown.

Next, with reference to FIG. 5, the first sleeve 40a is subjected to ashrinking procedure, such as heat shrinking, such that the dimensions ofthe first sleeve 40a are significantly reduced and the first sleeve 40asnugly engages the first end portion 46 of the balloon 18 in the firstgroove 36. In this manner, the first end portion 46 of the balloon 18 issecured in the annular first groove 36 of the catheter shaft 12 by theshrunk sleeve 40a without the use of adhesives or heat sealing.

The remaining portion of the balloon 18 is then folded over the outersurface of the first sleeve 40a. As illustrated in FIG. 6, the enlargedsecond shrinkable sleeve 40b is positioned over the second groove 38,and the remote second end portion 50 of the balloon 18 is folded to alocation intermediate the second sleeve 40b and second groove 83 withthe second end edge 52 of the balloon being directed toward the firstgroove 36. The second sleeve 40b is then subjected to a shrinkingtreatment, such as heat shrinking, in order to reduce the dimensions ofthe second sleeve 40b, as shown in FIG. 7. As shown, the shrunk secondsleeve 40b snugly engages against the second end portion 50 of theballoon 18 and secures the second end portion 50 of the balloon 18 inplace intermediate the second sleeve 40b and the second groove 38.

Thus, the end portions 46 and 50 of the flexible balloon 18 are securedbeneath the respective sleeves 40a and 40b in a simplified mannerwithout the use of adhesives or sealing techniques. After fabrication,the first end edge 48 of the first balloon end portion 46 is directedtoward the second groove 38 while the second end edge 52 of the secondballoon end portion 50 is directed toward the first groove 36. As shown,a central portion 54 of the balloon extends over the outer surface 26 ofthe catheter shaft 12 with side portions 56a and 56b overlying outersurfaces of the respective shrunk first and second sleeves 40a and b.With reference to FIGS. 1 and 7, the balloon may be inflated at the timeof use by passage of fluid through the tube 34, through the inflationlumen 22, and the wall aperture 28 into a cavity 58 defined intermediatethe central portion 54 of the balloon 18 and the outer surface 26 of thecatheter shaft 12. The balloon 18 may be deflated by reverse passage offluid from the cavity 58 through the inflation lumen 22 and the tube 34.

The foregoing detailed description is given for clearness ofunderstanding only, and no unnecessary limitations should be understoodtherefrom, as modifications will be obvious to those skilled in the art.

I claim:
 1. A catheter, comprising:an elongated shaft having a pair offirst and second spaced annular grooves in an outer surface of theshaft; an inflatable balloon comprising an elongated sleeve of flexiblematerial having first and second end edges adjacent opposed first andsecond end portions of the balloon; and a pair of first and secondrelatively rigid annular retaining sleeves, said first end portion ofthe balloon being snugly received intermediate the first retainingsleeve and the first groove with said first end edge of the balloonbeing directed toward said second groove, and said second end portion ofthe balloon being snugly received intermediate the second retainingsleeve and the second groove with said second end edge being directedtoward the first groove, with intermediate side portions of the retainedballoon overlying outer surfaces of the retaining sleeves prior toinflation of the balloon said retaining sleeves each being of one-piececonstruction circumferentially and across the width of the sleeves, andsaid sleeves being shrunk into the retaining configuration in arelatively rigid and inelastic condition with an internal diameter lessthan the outer diameter of the shaft.